Automatic injection device, including an ampoule or a cartridge for an injection device

ABSTRACT

Automatic injection device, as well as ampoule or cartridge for the same. In order to obtain a high speed discharge of an ampoule-hypodermic needle, as well as to ensure an operationally reliable, low weight, robust small apparatus or ampoule at long storability, sterility and re-usability of components for a plurality of injection substances, the needle body (30) of the cannulahypodermic needle (3) is constructed over part of its extension as a needle bearing (31) guided in sliding fit on the inner wall (21) of the cartridge (2). Particularly with a view to administering separate injection substances, it is provided for a cartridge or ampoule with needle and lifting element, that within the ampoule there is arranged a receptacle forming a gas volume, which receptacle can be destroyed easily by initiating the lifting movement and which is resistant to the injection fluid surrounding it.

The invention relates to an automatic injection or hypodermic device,including a cartridge or ampoule, which is mounted in a casing, receivesan injection substance, has a lifting element, surrounds an injection orhypodermic needle comprising an elongated needle body and a cannula ortubule. The needle being movable by the lifting element and has cannulainlet opening for the injection substance in the region of itsdrive-side end A seal arranged on the side of the needle point permitsthe passage of the needle shaft. An injection pressure device mounted onthe casing applies a force to the lifting element. A release mechanismputs the pressure device into operation; and includes a safety devicefor blocking the release mechanism. A cartridge or ampoule for use ininjection devices, particularly in an automatic hypodermic syringe, hasan injection substance in the cartridge or ampoule that is ejectable, asa result of the lifting movement of a lifting element, such as inparticular a plunger or bolt, through a cannula of an injection needlemounted on the cartridge or ampoule.

An automatic self-injection syringe gives unskilled persons anopportunity to make a subcutaneous or intramuscular self injection. Thishas particular significance in connection with the injection of atropinesulphate as a nerve gas preventative. In addition, atropine is injectedas an effective antidote in the case of insecticide poisonings. Atropineis also injected, e.g. in the case of spasms and colics in thegastrointestinal tract, in the gall bladder or the discharging urinarypassages, of bladder tenesmus, of hypersecretion of the stomach, ofgastric and duodenal ulcers, bronchial asthma and in higher doses andover longer periods in the case of Parkinsonism. An automatic injectiondevice can, in general, be used for the application of a large number ofinjection substances in human or veterinary medicine. Possibilities ofuse also exist in the technical field. Thus, in particular dangerous ortoxic substances can be introduced into soft materials, mention being,for example, made of the preservation of soft wood or similartreatments. The injection substances can be constituted by liquids,gases or pressure-liquifiable substances.

Essential demands made on an automatic injection device consist insterility, durability and stability even over long storage periods, invery rapid and reliable penetration of tissue parts having painreceptors by the needle, if necessary also after piercing articles ofclothing, in low weight and compact construction, as well as in simpleand operationally reliable handling.

In a known injection device of this type, a needle is mounted in anampoule by localizing a needle base on a lifting plunger, as well as onthe discharge side in a needle guide and a rubber plunger. A helicalcompression spring engages the ampoule sleeve for advancing the liftingplunger. In the case of such a construction, the guidance and mobilityof the needle are impaired due to the decelerating effect of therelatively long rubber bearing and this can lead to a moment of forcehaving an unfavourable action on the alignment and movement of theneedle. A cannula opening provided on the needle base, i.e. a weakenedneedle portion at this point, can lead to a deformation or even breakageof the needle. To ensure that an adequate force is applied to thelifting plunger or for driving the needle, a relatively high force isrequired, which has to be imposed by the relatively long helicalcompression spring having a relatively large coil diameter, the springfollowing the plunger in an inner sleeve mounting both it and theampoule, and engaging in the latter during operation. The ampoule bodyis made from stainless steel in order to withstand the force stressing.Due to catalytic effects and chemical and/or galvanic reactions of themetal with the injection substance, the stability and effectivenessthereof is reduced. Stainless steel is not inert for many injectionsubstances, so that it cannot be used as ampoule material. The pressuredevice and, therefore, the complete device have relatively largedimensions, the force efficiency and force guidance being restricted andunfavourable due to constructional conditions. The construction alsoleads to the risk of inadequate sterility and prevents re-use orreconstruction of the device. In a further known injection device (DE-AS14 91 842) the needle bearing comprises a plunger with a deformablepiston which can yield back into a cylindrical chamber so that mountingand construction are complicated, whilst the usability and efficiencyare restricted by constructional and material requirements.

Other automatic injection devices not belonging to this species comprisea needle fixedly attached to a movable ampoule (DE-OS 24 31 347, DE-AS19 34 117, DE-PS 24 36 000), a cap of an injection cannula being moreparticularly mounted on a needle holder (DE-OS 33 42 407).

In contrast thereto, the present invention is based on the task toprovide an automatic injection device, which ensures a high speedejection of the injection needle, whilst providing a uniform and clearlydefined injection substance release, the arrangement and construction ofthe needle bearing being intended render usable, in an optimum manner,or to improve the possibilities of use and application, the constructionand characteristics of the needle, cartridge, drive or pressure device,release mechanism and safety device, and, at the same time, the completedevice having a long storability as well as a sterility ensuring type ofconstruction of a particularly high mechanical efficiency, beingprovided to become operationally reliable, lightweight, robust, compact,of small construction, as well as simple, fast and without risk tohandle and to become, owing to the possibility of a cartridgereplacement and of the repeated use of device parts, reusable. A furtherobject of the invention is to provide a compact cartridge or ampoulecapable of being handled as such for an injection device, which shall beeffortlessly insertable into an injection device as an independentcomponent and which shall open up the random usability of an injectiondevice for a multitude of injection substances, particularly also theadministration of separate and, therefore, also injection substances notliquifiable per se and chemically reacting with one another onadministration, a construction being aimed at which is simple andfail-safe as well and meets medical requirements by a high degree, sothat, the ampoule or cartridge is particularly suitable for use inautomatic injection devices.

The problem is solved with respect to an injection device and to acartridge or ampoule insertable therein of the types described in theintroduction, in that the needle body, over part of its extension, isdesigned as a needle bearing guided in a sliding fit on the inner wallof the cartridge. In the case of an ampoule or cartridge of the typedescribed in the introduction, for the administration of separatedinjection substances, a receptacle such as a capsule forming a gas ordead volume is arranged within the ampoule, the receptacle having areceptacle wall resistant to the injection substance surrounding thereceptacle, which receptacle wall is, in particular, not soluble in theinjection substance and can easily be destroyed on initiating thelifting movement.

In the case of the integrated needle bearing formed by the needle body,it is, in particular, important that the needle or cannula isindependently movable and guided in the ampoule in substantiallyfriction-free manner with a type of floating effect in the injectionsubstance. Thus, the needle can be advanced very rapidly in asubstantially delay-free manner, and a high discharge capacity can beobtained. The needle bearing according to the invention is in itselfsufficient to guide and position the needle, so that there is no needfor further needle bearings, particularly in the ampoule dischargeregion. During operation the needle is also protected against damage ordestruction and its movement and alignment are substantially free fromthe influences of the mounting of the lifting element or its movementbehaviour. This means that the needle bearing is mechanically decoupledwith respect to the lifting element or to a pressure device such thatthe transmission of force to the needle takes place without anydisadvantageous effect on its alignment and whilst preventing damagethereto. This leads to a particularly simple, compact, robust,efficient, operationally reliable and easily handable ampoule and to aninstrument with corresponding advantages, whose components are notimpaired by the needle bearing as regards sterility as well as operationand re-usability, but can be provided with optimum adaptation andmatching thereto.

If a precisely central ejection of the needle is desired, althoughunnecessary for automatic injection, a spacer disk supporting the needlealignment can be arranged within the ampoule, and preferably in theneedle ejection region, which disk does not impair the substantiallyfrictionless mobility of the needle obtained in accordance with theinvention.

An embodiment of the needle bearing, according to the invention,consists in that it is constructed as a lifting element or a drive-sidesealing element, it being integrated into a lifting plunger or beingprovided with a preferably thin-walled surface serving the needleadvance and, in particular, being chargeable with the force of a fluid.Thus, the ampoule is made particularly small and the needle bearing canserve to the precise guidance and alignment of the lifting plunger orcan itself act as the lifting element, the sliding fit, in part, formingthe drive-side sealing of the ampoule.

It is particularly expedient for the needle bearing, in the case of acylindrical cartridge or ampoule, to comprise at least one cannulawinding establishing the sliding fit and, in particular, a terminalwinding engages on a lifting element constructed as a lifting plunger.Such a winding cannula ensures a moment-free self-mounting of theneedle, the sliding surface and, therefore, also the friction surface onthe ampoule inner wall is minimized. A single winding leads to aparticularly short cannula or needle. In accordance with the desiredresidual displacement volume, two or more windings can be shaped inclosely juxtaposed or spaced manner. Particularly in the case of massproduction, a particularly dimensionally accurate alignment of theneedle point perpendicularly to the winding body is ensured with respectto a central passage through the ampoule seal. Due to the design of theneedle bearing as a cannula winding the needle may as well be aligned ina particularly simple manner at an angle of approximately 7°-15° withrespect to the axis of the ampoule (cartridge or phial) or of thewinding. The amount of the adjusted angle deviation from the axis isprovided in accordance with the anatomical circumstances and facts. Itis e.g. advantageous to choose a relatively large deviation forself-injections in the posterior region. The engagement of the terminalwinding on the lifting plunger effects a delay-free, i.e. rapid forcetransfer possible under high force. An arrangement of the cannula inletopening on the plunger-side winding end ensures an optimum fluid entryinto and fluid passage through the cannula.

An injection substance quantity as well as a desired administration orapplication depth for the needle are expediently provided by the numberof cannula windings and matched thereto with a compressible gas or deadvolume i.e. in particular with a gas or air cushion leading to a defineddelay of injection substance discharge.

According to a further development of the invention, it is provided thatthe needle is located in a front, separate ampoule space forming a deadvolume and filled with a gas or gaseous mixture and to which on thedrive side is connected a rear ampoule space containing the injectionsubstance, separated by a sealing lifting element and formed between thelatter and a lifting plunger; and the lifting element can be piercedduring actuation by a formation in or on the needle and/or the needlebearing, said formation including the cannula inlet opening. Thus, thereis obtained a cannula mounted in a dry manner in an air or gas space andwhich is therefore kept sterile. The dead volume, which is compressibleto a higher degree with respect to the injection substance, additionallyleads to a very short, defined delay of the discharge of the injectionsubstance from the driven needle, i.e. the needle point exits from theampoule prior to the ejection of injection substance, the delay beingdetermined by the size of the dead volume and/or the distance of theopen needle end to the lifting element. The gas or dead space located indefined manner in the front ampoule part ensures a delay independent ofthe alignment of the ampoule during injection. Freedom from blocking ofthe cannula opening is, in particular, ensured by a sufficient openingcross-section and/or an opening remote from the needle impact zone. Theformation in or on the needle forming the needle end can be providedwith a grinding and/or made pointed to facilitate penetration of thelifting element.

For a cartridge or ampoule for loading an injection device, or for anampoule with a needle bearing according to the invention and/or theautomatic injection device of the aforementioned type, the inventionproposes that within the ampoule, in particular, between the needlebearing and the lifting element there is provided a gas- ordead-volume-forming receptacle, such as a capsule with a receptacle wallresistant to, in particular, not soluble by the injection substance,which receptacle can be destroyed easily by initiating the liftingmovement. This leads to a dead volume arranged in the ampoule in aconstantly defined manner and which is chemically and mechanicallylimited with respect to the injection substance without the aid of alifting or plunger element and is only released in the case of a givenpressure destruction. For the planned destruction of the receptacle and,at the start of injection, in order to permit the injection substancepresent in the region of the destroyed container to flow substantiallyinto the cannula inlet opening, optionally in a delayed manner as aresult of its immediate entry into a gas-dead-volume space, it is, inparticular, provided that the needle and/or needle bearing has aformation therein or thereon engageable with the receptacle wall andleading to the destruction of the dead volume receptacle upon pressureapplication, which formation has, in particular, a pointed cannula enddirected onto the receptacle wall, in particular, arranged adjacentthereto, the cannula inlet opening, for the purpose of flowing-in of theinjection substance occurring upon destruction of the receptacle, beingprovided, in particular, free of obstruction by jamming, on theformation, especially with an adequately large inlet cross-sectionand/or remote from the receptacle wall. It is particularly expedient forthe receptacle to contain at least one substance which, together withthe ampoule contents engaging on the undestroyed receptacle, produces aninjection substance to be administered. Thus, it is achieved that thesolid, liquid and/or gas in the capsule are held separated from theinjection substance, namely a solvent or a liquid injection mediumengaging thereon, and kept ready and that, when the capsule is destroyedin the defined manner there is a mixing of liquids or a dissolving ofsolid and/or gas, so that a resultant injection substance flowing intothe cannula opening is produced.

The self-mounting of the needle permits, in a particularly expedientmanner, the ampoule to be designed as a receptacle of glass or similarmaterial chemically resistant to the injection substance. As a result ofthe inventive needle bearing type according to the invention, theampoule wall is free from unfavourable forces, so that glass can be usedadvantageously as the material not attacked, e.g. by an atropinesulphate solution.

With a view to a particularly compact construction, a replacement of anampoule and/or substantially unlimited stability for a large number ofinjection substances, a particularly advantageous possibility consistsin the cartridge or ampoule seal of the glass ampoule being designed asa silicone plate with a beaded tin plate rim, the needle being providedto lie completely in the interior of the ampoule and the plate to bepenetrated by the needle. In place of silicone for the plate or tinplate for the beaded edge, it is possible to use other materials,particularly hardened plastics, which are inert with respect toinjection substances and which satisfy mechanical and constructionalrequirements.

A cannula outlet opening provided with an outlet grinding favours,particularly, a rapid penetration of tissue parts having pain receptorsand safeguards minimizing of trauma due to high cutting action.Moreover, a defined fluid release to be obtained according to theinvention, particularly at low injection solution quantity, effectslimited tissue pressure conditions.

In order to make interfaces coming into contact with injection fluids,such as the plate seal, the needle and a lifting element inert, thesealing plate consists of silicone or a plastic suitable in accordancewith the injection substance, the cannula consists of a V2A or V4A steelbringing about a very good sliding action between the ampoule inner walland needle bearing, and the cartridge or ampoule plunger consists ofchlorinated or chlorobutyl caoutchouc or a plastic material depending onthe injection substance.

Particularly for a simple changeover and for an easy replacement of theampoule presenting these possibilities and having an integrated needlebearing, an embodiment of the automatic device according to theinvention has, as its casing, a jacket casing and a closure caplaterally closing the casing in the region of the ampoule seal andmounting the cartridge or ampoule. It is particularly appropriate todesign the closure cap as a spring catch arrestable by means of grooveand tongue means and insertable into the jacket casing.

In the case of an injection device with a pressure device, whichcomprises a helical compression spring, a spring sleeve and a tappet orpiston driving the lifting element as a result of spring pressure, aparticularly advantageous embodiment of the device, made possiblethrough the needle bearing according to the invention and the thusresulting construction of the ampoule, consists in that the spring isarranged and kept tensioned between a jacket casing and the springsleeve, the spring sleeve is mounted displaceably on the jacket casingand is operatively connected to the piston and the cartridge or ampouleguiding and mounting the needle body in sliding fit directly on theinner wall thereof is so arranged that it extends into the arrangementarea of the tensioned spring, in particular enveloping the ampoule, i.e.to this extent being directly above it. This arrangement leads to aparticularly robust, functionally reliable, small injection deviceensuring a high spring or driving force and therefore being efficient.Thereby, in particular, it is significant that only the piston is driveninto the cartridge or ampoule, whilst the spring is separately mountedoutside the cartridge between the jacket casing and spring sleeve, evenin the case of untensioning thereof, i.e. comes into action outside theampoule. The spring sleeve driving the piston ensures a particularlystabilized force action, i.e. a trouble-free, precisely aligned, linearpiston drive. The force action and transmission, as well as the spacialarrangement within the device are particularly favourable, because thepower source, i.e. the spring, is located in the vicinity of the ampoulelifting element in space-saving manner on the outside between the jacketcasing and the ampoule even in the tensioned state. Thus, the ampoule ismounted in a very shockproof and, therefore, shatterproof manner. Thus,a particularly strong construction or dimensioning of the spring, i.e. ahelical spring with a relatively large diameter and thick springmaterial whilst being tensionable to the smallest space is possible, butthe particularly small construction of the overall device is notimpaired. The free, independent ampoule needle bearing ensures such acompressed construction safeguarding a high driving force. This is, inparticular, achieved in that the jacket casing is designed as acylindrical, stepped sleeve with a front portion substantiallysurrounding the ampoule and a rear portion following thereafter via ashoulder and having a diameter smaller by the shoulder as compared withthe front casing portion, the spring sleeve is mounted in the rearcasing portion and also on the cylindrically designed ampoule in amovable manner and in the tensioned state of the pressure device,overlaps the same substantially along the extension of the tensionedhelical compression spring, the spring being kept tensioned between theshoulder and an annular projection arranged at the overlapping end ofthe spring sleeve. When the device is in the tensioned state, thisstructure permits that the tappet of the piston is arranged to lieupstream of the inner end of the ampoule and outside the latter and thata tappet-side ampoule lifting element, particularly a lifting plungerterminates substantially with said end, a second lifting elementenclosing a compressible space with the tappet-side lifting element,when necessary, being provided on the needle side, and that the pistonis mounted at its rear end on the spring sleeve and is consequentlydrivable in the direction of the needle. It can be seen that the deviceis advantageously constructed with a spatially outwardly closed ampoule,the force being transferable to the needle-side lifting element via asuitable compressible space. When the device is in the tensioned state,it is also possible for the piston to enter the ampoule and pass throughthe helical spring, thereby engaging with its tappet on the plungermounted at its other, rear end on the spring sleeve so that it isconsequently drivable in the direction of the needle. The rear, taperedcasing portion forms a space-saving, movement-stabilizing sleevefriction bearing for the spring sleeve, little space being required forthe helical compression spring and the latter being located in aspace-saving and space-utilizing manner between the casing jacket andampoule and parallel to the latter, its operation not having adisadvantageous effect through the external arrangement thereof on thespring sleeve, so that, in particular, it is possible to use a per sefragile glass ampoule made possible through the needle bearing typeaccording to the invention.

The needle bearing or ampoule design according to the invention enable afurther development of the invention with a view to a particularlycompact as well as sterility-ensuring construction of the device and/orparticularly with respect to re-usability of device parts, whichdevelopment resides in that in a known per se manner the releasemechanism comprises a release sleeve which is axially displaceablyarranged on a jacket casing and a release element movable therewith, aswell as a spring element connected to the pressure device, arrested onthe jacket casing and thereby keeping the pressure device in thetensioned state, the spring element being releasable from its springseat when the release element strikes against it, and consequently thepressure device being releasable. Thus, the aforementioned subdivisionof the jacket casing into a front and a rear portion enables, for thefurther improvement of the handy and practicable use of theself-injection syringe, that the release sleeve be small, easilyoperable and displaceably mounted on the rear, offset casing portion,only, in sliding fit in the direction of the shoulder.

In order to avoid an undesired release of the syringe, the instrumentaccording to the invention can be equipped with a known per se safetydevice for a particularly reliable and effective operation, which safetydevice comprises a safety element with an engagement element engaging onthe piston and keeping the same locked against the force of the spring.With regard to easy fitting possibilities and taking account of re-use,it is particularly appropriate for the safety element designed as asafety button to be mounted on a beaded rim frontally designed on therelease sleeve and simultaneously forming the release element, and forthe engagement element designed as a button pin or plug to engage in therear end of the piston, which end is designed as the release springelement.

The individual parts of the device according to the invention as well asthe latter itself can be inexpensively mass-produced. The combination ofthe parts leads to a particularly safely functioning, short device,ensuring the sterility necessary for injection. Inexpensive plasticcasing parts can be made impermeable to light, so that even when usingadvantageous glass ampoules, light protection and therefore long-termstorage are ensured. A helical compression spring is expedientlyconstructed as a galvanized steel spring, which can, in particular, havea high spring pressure, without impairing the operational or functionalreliability of the components and, in particular, of the ampoule. Theglass ampoule embodiment leads to an only weak magnetic ampoule ordevice, in other words it is not unfavourably influenced in this respectfrom the ambience. The advantages attainable according to the inventionare, in particular, that an automatic syringe and a cartridge or ampouleare obtained which, in the case of a construction ensuring sterility andhigh storage stability, are particularly handy, practical, operationallyreliable and efficient, the ampoule enabling defined arrangements of gasor dead volumes, as well as the use of substantially all possiblyrelevant injection substances and, in particular, such substances whichare separated, to be mixed or to be dissolved. Unskilled persons aregiven the possibility of an almost painless administration of an eithersubcutaneous or intramuscular self-injection. There is a possibility ofa simple changeover and replacement of injection ampoules, together withthe re-use of device parts. The needle/ampoule design according to theinvention or the material structure attainable therewith for an ampoule,as well as the simple and reliable manner of construction and ofoperation resulting from the pressure device, release mechanism andsafety device enable an almost unlimited life for a large number ofinjection substances, as well as a particularly safe operation meetingthe particular requirements of medical application, the cannula passingout very rapidly so as to ensure freedom from pain and, depending on thepositioning of an injector, it can optionally pierce clothing and a fewmillimetres of skin surface, without any injection fluid emerging when adead volume is provided, but this is followed by a very rapid anddeliberate fluid ejection.

BRIEF DESCRIPTION OF THE DRAWINGS

Further utilities, developments and embodiments of the invention can begathered from the following description of the drawings.

FIG. 1 is a side section view of an injection device in accordance withthe invention with an ampoule mounted therein;

FIGS. 2 to 4 are views of injection needles in accordance with theinvention;

FIGS. 5a and 5b an ampoule in accordance with the invention with asterile-manner mounted needle; and

FIGS. 6a and 6b are section views of an ampoule in accordance with theinvention with a capsule and floating needle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to FIG. 1, an automatic injection device 1, which is in itstensioned state, comprises a one-piece, cylindrical jacket casing 10with a front casing portion 101 and a smaller diameter rear casingportion 102 stepped with respect to the former by means of a shoulder103. The front end of the injection device 1 is closed by a closure cap11. An ampoule 2 in accordance with the invention is inserted in thecasing portion 101 and is arrested with an unlockable snap catch havinggroove and tongue means 110/111. On the rear casing portion 102 there isprovided, in sliding fit, a release sleeve 12 terminally closed with asafety button 13 as a safety element and which is held with a recess 123in the sleeve and with an all-round thickened casing portion 124 on therear casing portion 102. The latter mounts internally in sliding fit acylindrical spring sleeve 41, which in turn mounts the ampoule 2 insliding fit and can move over and beyond the same.

The ampoule or cartridge 2 in accordance with the invention as shown inFIG. 1 is designed as a cylindrical glass receptacle, which is sealed tothe outside on the front side of the ampoule with a silicone plate 23comprising a tin plate beaded rim 231. An injection fluid 25 iscontained in the ampoule and preferably includes a solution of atropinesulphate, acid for pH-value setting, e.g. hydrochloric acid, a suitablesalt for isotonization, e.g. sodium chloride and water for injectionpurposes. The injection fluid is between seal 23 and a liquid-sealinglifting plunger 22 lifting which is used as the element. Glass as thematerial for ampoule 2 ensures, over a long period, that the injectionsolution is maintained sterile and pyrogen-free, with suitable tonicity.Further, the desired pH-value can be maintained, whilst ensuring freedomfrom impurities according to standard purity criteria. Due to lowthermal conductivity of the glass receptacle 2, heat transfer to theinjection fluid, which can occur in the case of conventional metalampoules, is avoided, so that the fluid is protected againstdecomposition by high temperatures and to this extent is kept stable.

In the case of the injection device according to FIG. 1, the liftingplunger 22, slidable in the ampoule 2, is located in the area in frontof the inner end 410 of the spring sleeve 41. The rear end region 24 ofampoule 2 extends into the spring sleeve 41 up to the area of the casingshoulder 103. Outwardly, plunger 22 engages a tappet 422 of a piston 42,which, by means of an all-round bead 424 on the rear end 411 of thespring sleeve 41, is movable in the direction of the lifting plunger 22,the latter being advanceably mounted in the ampoule 2.

There is provided a hypodermic or injection needle 3 positionedcompletely within the ampoule 2, i.e. located in the fluid 25 betweenthe seal 23 and the lifting plunger 22. It is designed as a windingcannula with two terminal cannula windings 311, 312, which, as windingbodies, form a needle bearing 31, in that the outer faces of thewindings directly establish a sliding fit on the ampoule inner wall 21.The outer winding 312 forms a substantially planar abutment for thelifting plunger 22, so that the winding body can be driven forwardlylinearly in the direction of its axis or the central axis of the ampoule2 by means of the lifting plunger 22. With respect to a particularlysmall construction, and for establishing a bearing for a liftingplunger, it is appropriate to embed the winding body at least partly inthe lifting plunger, whilst leaving free the winding's sliding faces.The winding 311 passes into an elongated cannula-needle body 30, whichis aligned precisely in the ampoule central axis 26. To assist aprecisely central alignment and guidance, it is possible to provide aspacer element not impairing a floating mounting of the needle and thefree mobility thereof, in particular a spacer disk 27, indicated inbroken line form, in the front area of the ampoule. The cannula is openat the end of the winding 312 by means of a cannula inlet opening 34located on the lifting plunger 22 in the area of the abutment of theneedle bearing 31. The needle point has a cannula outlet opening 33provided with a grinding, which, during the ejection or drive of theneedle 3, pierces the seal 23 in the axial direction 26. Immediatelyfollowing the piercing, the fluid 25 is ejected through the cannula 30,31 provided with the windings 311, 312.

In FIG. 2 a front and a longitudinal view of the hypodermic needle 3inserted in the ampoule according to FIG. 1 are represented. By means ofthe needle bearing 31, i.e. by the needle body substantially having twowindings 311 and 312, bearing and sliding surfaces for the ampoule innerwall 21 are formed in the axial direction and transversely thereto onthe circumference of the winding body, as can be seen at 313 and 314.The inlet opening 34 is positioned in protected manner within thewinding body 31. The needle bearing in accordance with the invention canas well be provided with a winding body 31, essentially comprising oneturn 312, only, as shown in FIG. 3. As shown in FIG. 4, a furtherembodiment for a needle 3 consists in that a terminal winding 312 is notclosed completely, in that an aperture angle of, for example, 30°remains. An exact needle alignment and guidance is ensured with such areduced winding construction, as well, because the needle body or needleshaft 30, in particular, floats in an injection fluid and is keptcentred thereby. The described termina windings 312 are terminated witha winding surface 315 perpendicularly to the needle axis 26 at the end.With a view to obtaining a particularly short ampoule, it isparticularly possible to mount or attach a thin-walled, closed surfaceelement on a terminal turn 312 as is indicated by the hatched area inFIG. 4. Thus, the needle bearing is itself designed as a lifting elementor a drive-side sealing element, so that there is no need for a separateampoule plunger.

In FIG. 1, a pressure device 4 of the automatic injection device 1comprises a spring sleeve 41, the piston 42 and a helical compressionspring 40. The latter is kept tensioned in a space-saving mannerexternally on the spring sleeve 41 between the ring projection 410 andthe shoulder 103 and thus is arranged between the casing portion 101 andthe spring sleeve 41 in the rear end region 24 of the ampoule 2. Thisarrangement and space subdivision permit the use of a stronglydimensioned, i.e. a high spring energy-holding spring. The pressuredevice 4 or the spring 40 are tensioned by means of the rear end 423 ofthe piston 42, in that the end engages a mushroom-shaped spring element421 against a terminal opening rim 104 of the casing portion 102.

A release mechanism 5 has a release sleeve 12 with a release elementconstructed as a rim 121 that is concentric to the mushroom head of thespring element 421, which rim compresses the mushroom head by strikingagainst the same and consequently setting free the piston spring element421 for the piston movement due to the force of the spring 40.

A safety device 6 has, as a safety element, the safety button 13inserted in the rim 121 with a pin or plug 131, which engages in agroove of the mushroom head spring element 421, so that it is notcompressible with the release element 121 and consequently the spring isreliably arrested in the tensioned state.

The casing components 10, 11, 12 and 13, as well as the ampoule seal 23are designed as inexpensive, light-impermeable plastic elements. Theglass ampoule 2 with the integrated sliding needle bearing 31 incombination with the snap cap 11 mounting the same, as well as with thearrangement and subdivision of the described components permits there-use or new use of the device 1, with removability of the releasesleeve 12 as well by unlocking locking device 123/124, in that thecompact ampoule 2, which particularly meets medical requirements, can besubstituted simply and the spring 40, designed as a galvanized steelspring, can be re-tensioned rapidly and easily, whereby the components10, 40, 41 and 42 can consequently be used anew without replacement. Theoverall construction is short and has a limited weight, but this doesnot impair the robustness of the automatic injector.

The automatic injection device in accordance with the inventionadvantageously permits a liquid ejection quantity of approximately 0.7 gand a cannula exit length (between cannula tip and outer wall of theampoule seal) of approximately 23 mm. The cannula exit time can, at aspring pressure of approximately 10.5 N/m², be approximately 0.5 s. Thecompact structure, in particular, permits an overall length ofapproximately 103 mm at a diameter of approximately 15 mm. Tests haveshown that the ampoule with integrated winding cannula mounting ensuresthat, in the case of a dead volume provided at the cannula inlet openingduring administration, the injection fluid immediately following thereleasing of the device initially does not exit from the cannula, but isonly ejected after penetrating a few millimetres of skin surface. Thus,the liquid discharge takes place in a defined and uniform manner andconsequently establishes a favourable physiological depot in differingbleeding and tissue structures.

An ampoule, in accordance with the invention and to FIG. 5, comprises anair or gas space 291, in which is held, guided and mounted, in a sterilemanner, a hypodermic needle 3 with a needle bearing 31 comprising onewinding 310. To the space is connected, by means of a lifting-sealingelement 29, an ampoule space 292 containing an injection solution 25 andwhich, on the drive side, is closed by a rubber plunger 22 as thelifting element. As can be taken from FIG. 5a, the plunger 22 comprisesa dead volume or an air space 22 when the ampoule is in itsnon-operative state. Towards the side of the sealing element 29, theneedle 3 has a spear-shaped formation 35 located in the ampoule axis 26and comprising an inlet opening 34. Due to the easier compressibility ofthe gas space 291 as compared with the injection solution space 292,prior to its entry/passage of the tip 35 into or through thelifting-sealing element 29, the needle 3 is driven in liquid-free mannerthrough the ampoule seal 23 over a given length and only then, as shownin FIG. 5, there occurs an inflow of liquid into the inlet opening 34through the cannula. Together with the passage strength of thelifting-sealing element 29, the formation 35, dependent on the degreesof compression and/or volume in the two spaces 291, 292, determines thethus defined delayed liquid discharge.

A cannula, in accordance with the invention and to FIG. 6, comprises acapsule 28 arranged between the injection substance space 293 andlifting plunger 22 and which has a capsule wall 295 chemically resistantto injection fluid 25. Due to the charging with pressure, the capsule294 disintegrates (FIG. 6b), this destruction being initiated by aspear-shaped formation 35 having a cannula inlet opening 34. The capsule294 is at least partly filled with solid, liquid and/or gas 294, twopreviously separate fluids being mixed or a solid and/or a gas beingdissolved in liquid during or after capsule destruction, so that aresultant injection substance is obtained, which flows into the inletopening 34 in a concentration forming in the capsule destruction areaand is ejected with the complete ejection of the needle 3. It is,therefore, made possible to inject injection substances or injectioncomponents which have been kept separately, the direct arrangement ofthe formation 35 or the inlet opening 34 on receptacle wall 295, asshown in FIG. 6b, making it possible to ensure a delayed injectionsubstance outlet due to the gas present in the capsule. The cannulawinding bearing 31 in accordance with the invention, together with theneedle body 30 floating in the injection solution 25 ensures an optimummounting and guidance of the needle 3.

We claim:
 1. An automatic injection device, comprising: a casing, anampoule mounted in the casing and having an injection fluid, a liftingelement, an injection needle having a needle point, an elongated needlebody and a cannula wherein the needle is moved by engagement of thelifting element with an end portion of the needle opposite the needlepoint, a cannula inlet opening for the injection fluid disposed in theregion of said one end, said ampoule having a seal adjacent the needlepoint such that the needle point pierces the seal and permits passage ofthe needle therethrough when the needle is moved by the lifting element,injection force means mounted on the casing for applying a force to thelifting element, release means for releasing the injection force means;and said needle having a needle bearing having at least one winding thatis formed as a unitary part of the needle body and that has an outersliding surface that is guided in a sliding fit on an inner wall of theampoule.
 2. An injection device according to claim 1, further includinga spacer disk supporting the needle in alignment within the ampouleadjacent the needle point of the needle.
 3. An injection deviceaccording to claim 1, wherein the needle bearing includes a liftingelement integrated into a lifting plunger that is acted upon by saidinjection force means.
 4. An injection device according to claim 1,wherein the ampoule is cylindrical and the needle bearing has twowindings for establishing the sliding fit between the needle bearing andthe inner wall of the ampoule.
 5. An injection device according to claim4, wherein said needle bearing includes a terminal winding as said endportion that engages the lifting element.
 6. An injection deviceaccording to claim 4, further including a predetermined number of saidwindings, and said ampoule having a predetermined dead space volume suchthat a desired injection fluid quantity and administration depth for theneedle are obtained.
 7. An injection device according to claim 1,further including said ampoule having a front space forming a deadvolume filled with a gas and the needle being positioned within saidfront space, and said ampoule further having a rear ampoule spacecontaining the injection fluid and being separated by the sealinglifting element at one side of the contained injection fluid and alifting plunger at the other side of said contained injection fluid; andsaid end portion of said needle having a piercing end and an adjacentcannula inlet opening for piercing said lifting seal element when saidlifting plunger is moved by said force applying means such that saidinjection fluid is dispensed through said cannula inlet opening fromsaid rear ampoule space.
 8. An injection device according to claim 1,wherein the ampoule has a receptacle means disposed between the needlebearing and the lifting element for forming a dead volume filled withgas, said receptacle means having a receptacle wall resistant to theinjection fluid and further being destroyed by movement of the liftingelement.
 9. An injection device according to claim 8, wherein said endportion of the needle is a piercing end positioned adjacent thereceptacle wall, and said needle further having a cannula inlet openingadjacent said piercing end for receiving the flow of injection fluidinto the cannula when said force applying means moves said liftingelement to destroy said receptacle wall.
 10. An injection deviceaccording to claim 8, wherein the receptacle has at least one substancecontained therein that combines together with the injection fluid whenthe receptacle wall is destroyed to produce an injection fluidcombination that is administered through the needle.
 11. An injectiondevice according to claim 1, wherein the ampoule is a receptacle that ischemically resistant to the injection fluid and is made from glass. 12.An injection device according to claim 1, wherein the ampoule seal has asilicone plate, and the needle is positioned to lie entirely within theinterior of the ampoule such that the plate is pierced by the needlepoint when the lifting element is moved by said injection force means.13. An injection device according to claim 1, wherein the injectionneedle has a cannula outlet opening adjacent the needle point, andfurther wherein the needle is made from one of V2A steel, V4A steel,Teflon, and hardened plastic.
 14. An injection device according to claim1, wherein the lifting element is made from one of chlorinated orchlorobutyl caoutchouc, silicone and hardened plastic that is inert withrespect to the injection fluid.
 15. An injection device according toclaim 1, wherein the casing has a jacket casing and a closure cap forlaterally closing the casing in the region of the ampoule seal, andfurther wherein said casing receives the ampoule.
 16. An injectiondevice according to claim 15, wherein the closure has a spring catchthat is inserted into the jacket casing and is arrested by groove andtongue means for preventing movement of the closure with respect to thejacket casing.
 17. An injection device according to claim 1, furtherincluding said injection force means having a helical compression springsurrounding a spring sleeve, a piston drivingly connected with saidinjection force means for driving the lifting element, the helicalcompression spring being positioned between the casing and the springsleeve in a tensioned state, said spring sleeve being mounted formovement with respect to the casing and being drivingly connected to thepiston, and the ampoule being received within the casing in alignmentwith the piston such that release of the tension in the helicalcompression spring moves the spring sleeve with respect to the casingand correspondingly drives the piston toward the lifting element formoving the lifting element.
 18. An injection device according to claim17, wherein the jacket casing has a cylindrical, stepped sleeve with afront end portion substantially surrounding the ampoule, a rear portionand a stepped portion between said front and rear portions, said steppedportion having a smaller diameter than the front portion to define ashoulder; the spring sleeve being mounted in the rear portion of thecasing and extending into the front end portion; and the ampoule beingreceived within the spring sleeve such that the spring is held intension between the shoulder and an annular projection extendingoutwardly from the spring sleeve at a portion of the spring sleeve thatreceives the ampoule.
 19. An injection device according to claim 17,wherein the piston is positioned in alignment with an inner portion ofone end of the ampoule and said lifting plunger is positioned withinsaid ampoule substantially at said one end; and a second lifting elementenclosing an ampoule space having compressible air contained thereinsuch that the piston is moved from an end opposite to the second liftingelement and is driven in the direction of the needle.
 20. An injectiondevice according to claim 17, wherein the piston is positioned inalignment with an inner portion of one end of the ampoule, the pistonhaving a tappet end portion that engages the lifting element and anopposite end portion that engages the spring sleeve for driving thetappet into engagement with the lifting element.
 21. An injection deviceaccording to claim 1, wherein the release means has a release sleevemounted for movement with respect to the casing in an axial directionand a release element facing a plug end of said spring sleeve such thatan axial movement of said release element releases the spring sleevefrom a first position relative to the casing wherein the helicalcompression spring is in a tensioned state so that said lifting elementis moved by helical compression spring driver movement of the springsleeve.
 22. An injection device according to claim 18, wherein therelease sleeve is mounted for relative sliding movement within the rearportion of the casing for movement in the direction of the shoulder. 23.An injection device according to claim 21, further including means forblocking the release of said release means including a safety devicehaving a safety element that engages an end of the piston opposite to anend engaging the lifting element for preventing movement of the pistonwith respect to the casing.
 24. An injection device according to claim23, wherein said safety element is a safety button mounted on a bead rimand facing the release sleeve and engaging the release sleeve plugelement for blocking the movement of said piston.
 25. An injectiondevice according to claim 1, wherein the needle bearing includes alifting element integrated into a lifting plunger having a thin-walledsurface that is acted upon by said injection force applying means.
 26. Acartridge for an automatic hypodermic syringe containing an injectionfluid, a lifting element and a hypodermic needle therein,comprising:said needle having a needle point, an elongated needle bodyand a cannula wherein the needle is moved by engagement of an endportion of the needle opposite the needle point with the liftingelement; the cannula having an inlet opening for the injection fluid; aseal for sealing the ampoule at the end adjacent a point of the needle,said needle point penetrating the seal when the needle is moved by thelifting element; and the needle having a needle bearing having at leastone winding that is formed as a unitary part of the needle body and thathas an outer sliding surface that is guided in a sliding fit on an innerwall of the cartridge.
 27. A cartridge according to claim 26, furtherincluding a spacer disk supporting the needle in alignment within thecartridge at the needle point side of the cartridge.
 28. A cartridgeaccording to claim 26, wherein the needle bearing includes a liftingelement integrated into a lifting plunger that is charged with the forceof a fluid.
 29. A cartridge according to claim 26, wherein the cartridgeis cylindrical and the needle bearing has two windings for establishingthe sliding fit between the needle bearing and the inner wall of thecartridge.
 30. A cartridge according to claim 29, wherein said needlebearing includes a terminal winding as said end portion that engages thelifting element.
 31. A cartridge according to claim 29, furtherincluding said needle bearing having a predetermined number of saidwindings, and said cartridge having a predetermined dead space volumefilled with a compressible gas such that a desired injection fluidquantity and administration depth for the needle are obtained.
 32. Acartridge according to claim 26, further including said cartridge havinga front space forming a dead volume filled with a gas and the needlebeing positioned within said front space, and said cartridge furtherhaving a rear cartridge space containing the injection fluid and beingseparated by the sealing lifting element at one side of the containedinjection fluid and a lifting plunger at the other side of saidcontained injection fluid; and said end portion of said needle having apiercing end and an adjacent cannula inlet opening for piercing saidlifting seal element when said lifting plunger is moved such that saidinjection fluid is dispensed through said cannula inlet opening fromsaid rear cartridge space.
 33. A cartridge according to claim 26,wherein the cartridge has a receptacle means disposed between the needlebearing and the lifting element for forming a dead volume space filledwith gas, said receptacle means having a receptacle wall resistant tothe injection fluid and further being destroyed by movement of thelifting element.
 34. A cartridge according to claim 33, wherein said endportion of the needle is a piercing end positioned adjacent thereceptacle wall, and said needle further has a cannula inlet openingadjacent said piercing end for receiving the flow of injection fluidinto the cannula when said receptacle wall is destroyed by movement ofthe lifting element.
 35. A cartridge according to claim 33, wherein thereceptacle has at least one substance contained therein that combinestogether with the injection fluid when the receptacle is destroyed toproduce an injection fluid combination that is administered through theneedle.
 36. A cartridge according to claim 26, wherein said cartridge isa receptacle that is chemically resistant to the injection fluid and ismade from glass.
 37. A cartridge according to claim 26, wherein thecartridge seal has a silicone plate, and the needle is positioned to lieentirely within the interior of the cartridge such that the plate ispierced by the needle point when the lifting element is moved.
 38. Acartridge according to claim 26, wherein the injection needle has acannula outlet opening adjacent the needle point, and further whereinthe needle is made from one of V2A steel, V4A steel, Teflon, andhardened plastic.
 39. A cartridge according to claim 26, wherein thelifting element is made from one of chlorinated or chlorobutylcaoutchouc, silicone and hardened plastic that is inert with respect tothe injection fluid.
 40. A cartridge according to claim 26, wherein theneedle bearing includes a lifting element having a thin-walled surfacethat is charged with the force of a fluid.
 41. A cartridge for anautomatic hypodermic syringe, comprising:a hypodermic needle having anelongated needle body and a cannula and being mounted in the cartridge;means for ejecting an injection fluid in the cartridge through thecannula of the hypodermic needle; said ejecting means including liftingmovement means for lifting a plunger; a receptacle contained within thecartridge for forming a dead volume having a receptacle wall that isinsoluble to the injection fluid and that contains at least onesubstance, and said wall being destroyed by said lifting means wherebythe substance is combined with the injection fluid to produce aninjection fluid combination that is administered through the needle. 42.A cartridge according to claim 41, wherein said hypodermic needle has aneedle bearing having at least one winding that is formed as a unitarypart of the needle body and that has an outer sliding surface that isguided in a sliding fit on an inner wall of the cartridge.